Worst and best irredundant sum-of-products expressions

In an irredundant sum-of-products expression (ISOP), each product is a prime implicant (Pl) and no product can be deleted without changing the function. Among the ISOPs for some function f, a worst ISOP (WSOP) is an ISOP with the largest number of Pls and a minimum ISOP (MSOP) is one with the smallest number. We show a class of functions for which the Minato-Morreale ISOP algorithm produces WSOPs. Since the ratio of the size of the WSOP to the size of the MSOP is arbitrarily large when it, the number of variables, is unbounded, the Minato-Morreale algorithm can produce results that are very far from minimum. We present a class of multiple-output functions whose WSOP size is also much larger than its MSOP size. For a set of benchmark functions, we show the distribution of ISOPs to the number of Pls. Among this set are functions where the MSOPs have almost as many Pls as do the WSOPs. These functions are known to be easy to minimize. Also, there are benchmark functions where the fraction of ISOPs that are MSOPs is small and MSOPs have many fewer Pls than the WSOPs. Such functions are known to be hard to minimize. For one class of functions, we show that the fraction of ISOPs that are MSOPs approaches 0 as n approaches infinity, suggesting that such functions are hard to minimiz

Mineralogical Alterations During Laboratory-scale Carbon Sequestration Experiments for the Illinois Basin

AbstractDuring geological sequestration of carbon dioxide, the injected CO2 will react with formation fluids and rocks in the injection zone and overlying cap rocks. The resulting acidification of the fluids may result in the dissolution of solid phases and the formation of new solid phases which can cause changes in rock composition and overall fabric. We are conducting laboratory-scale geochemical and mineralogical studies on reservoir and cap rock samples in the Illinois Basin that complement the on-going Illinois Basin - Decatur Project (IBDP), a large-scale one million tonne demonstration of geologic sequestration in the Mt Simon Sandstone, Illinois USA. Mt. Simon Sandstone, Eau Clare Shale, and Knox Supergroup samples from the IBDP injection and deep monitoring wells and locations with rocks analogous to those at the IBDP site have been selected for simulated reactions using synthetic brine and CO2 in modified Parr pressure reactors at pressure and temperature conditions that correspond to ambient reservoir conditions (9.87 to 20.7MPa and 38 to 50°C) and for varying amounts of time (1 to 9 months). Using petrographic techniques and XRD analysis, samples have been analyzed before and after reactor experiments to define the mineralogical and textural baseline and report observed changes. Brine composition has also been analyzed for geochemical changes. The React® and Differential Evolution geochemical modeling programs are being used to simulate changes in mineral mass and brine chemistry. Post-reaction analyses of rock and brine samples from the Mt. Simon Sandstone show evidence of dissolution of diagenetic clays, increased porosity, and possible illitization of clay minerals. Three, six, and nine month post-reaction Eau Claire Shale rock and brine sample analyses indicate some degree of brine-rock-CO2 reaction by showing weathered illite, mixed clay, feldspar, biotite, and pyrite crystals. Post-reaction Potosi Dolomite rock and brine samples show evidence of dissolution of dolomite. Overall, petrographic and geochemical observations from these experiments suggest that the Mt. Simon Sandstone reservoir and Eau Claire cap rock system serve as good CO2 sequestration site. The competency of the Knox Supergroup as a CO2 sequestration target is still under investigation

Pressure-induced phase transitions of halogen-bridged binuclear metal complexes R_4[Pt_2(P_2O_5H_2)_4X]nH_2O

Recent contrasting observations for halogen (X)-bridged binuclear platinum complexes R_4[Pt_2(P_2O_5H_2)_4X]nH_2O, that is, pressure-induced Peierls and reverse Peierls instabilities, are explained by finite-temperature Hartree-Fock calculations. It is demonstrated that increasing pressure transforms the initial charge-polarization state into a charge-density-wave state at high temperatures, whereas the charge-density-wave state oppositely declines with increasing pressure at low temperatures. We further predict that higher-pressure experiments should reveal successive phase transitions around room temperature.Comment: 5 pages, 4 figures embedded, to be published in Phys. Rev. B 64, September 1 (2001) Rapid Commu

A Boolean-based machine learning framework identifies predictive biomarkers of HSP90-targeted therapy response in prostate cancer

Precision medicine has emerged as an important paradigm in oncology, driven by the significant heterogeneity of individual patients' tumour. A key prerequisite for effective implementation of precision oncology is the development of companion biomarkers that can predict response to anti-cancer therapies and guide patient selection for clinical trials and/or treatment. However, reliable predictive biomarkers are currently lacking for many anti-cancer therapies, hampering their clinical application. Here, we developed a novel machine learning-based framework to derive predictive multi-gene biomarker panels and associated expression signatures that accurately predict cancer drug sensitivity. We demonstrated the power of the approach by applying it to identify response biomarker panels for an Hsp90-based therapy in prostate cancer, using proteomic data profiled from prostate cancer patient-derived explants. Our approach employs a rational feature section strategy to maximise model performance, and innovatively utilizes Boolean algebra methods to derive specific expression signatures of the marker proteins. Given suitable data for model training, the approach is also applicable to other cancer drug agents in different tumour settings.Sung-Young Shin, Margaret M. Centenera, Joshua T. Hodgson, Elizabeth V. Nguyen, Lisa M. Butler, Roger J. Daly and Lan K. Nguye

Characterization of halogen-bridged binuclear metal complexes as hybridized two-band materials

We study the electronic structure of halogen-bridged binuclear metal (MMX) complexes with a two-band Peierls-Hubbard model. Based on a symmetry argument, various density-wave states are derived and characterized. The ground-state phase diagram is drawn within the Hartree-Fock approximation, while the thermal behavior is investigated using a quantum Monte Carlo method. All the calculations conclude that a typical MMX compound Pt_2(CH_3CS_2)_4I should indeed be regarded as a d-p-hybridized two-band material, where the oxidation of the halogen ions must be observed even in the ground state, whereas another MMX family (NH_4)_4[Pt_2(P_2O_5H_2)_4X] may be treated as single-band materials.Comment: 16 pages, 11 figures embedded, to be published in Phys. Rev.

Prediagnostic smoking is associated with binary and quantitative measures of ER protein and ESR1 mRNA expression in breast tumors

Background: Smoking is a possible risk factor for breast cancer and has been linked to increased risk of estrogen receptor-positive (ER+) disease in some epidemiologic studies. It is unknown whether smoking has quantitative effects on ER expression. Methods: We examined relationships between smoking and ER expression from tumors of 1,888 women diagnosed with invasive breast cancer from a population-based study in North Carolina. ER expression was characterized using binary (±) and continuous measures for ER protein, ESR1 mRNA, and a multigene luminal score (LS) that serves as a measure of estrogen signaling in breast tumors. We used logistic and linear regression models to estimate temporal and dose-dependent associations between smoking and ER measures. Results: The odds of ER+, ESR1+, and LS+ tumors among current smokers (at the time of diagnosis), those who smoked 20 or more years, and those who smoked within 5 years of diagnosis were nearly double those of nonsmokers. Quantitative levels of ESR1 were highestamong current smokers compared with never smokers overall [mean (log2) = 9.2 vs. 8.7, P > 0.05] and among ER+ cases; however, we did not observe associations betweensmokingmeasures and continuous ER protein expression. Conclusions: In relationship to breast cancer diagnosis, recent smoking was associated with higher odds of the ER+, ESR1+, and LS+ subtype. Current smoking was associated with elevated ESR1 mRNA levels and an elevated LS, but not with altered ER protein. Impact: A multigene LS and single-gene ESR1 mRNA may capture tumor changes associated with smoking

A novel length back-calculation approach accounting for ontogenetic changes in the fish length – otolith size relationship during the early life of sprat (Sprattus sprattus)

(Sprattus sprattus), accounting for ontogenetic changes in the relationship between fish length and otolith length. In sprat, metamorphosis from larvae to juveniles is characterized by the coincidence of low length growth, strong growth in body height, and maximal otolith growth. Consequently, the method identifies a point of metamorphosis for an individual as the otolith radius at maximum increment widths. By incorporating this information in our back-calculation method, estimated length growth for the early larval stage was more than 60% higher compared with the result of the biological intercept model. After minimal length growth during metamorphosis, we found the highest increase in length during the early juvenile stage. We thus located the strongest growth potential in the early juvenile stage, which is supposed to be critical in determining recruitment strength in Baltic sprat

Affective Man-Machine Interface: Unveiling human emotions through biosignals

As is known for centuries, humans exhibit an electrical profile. This profile is altered through various psychological and physiological processes, which can be measured through biosignals; e.g., electromyography (EMG) and electrodermal activity (EDA). These biosignals can reveal our emotions and, as such, can serve as an advanced man-machine interface (MMI) for empathic consumer products. However, such a MMI requires the correct classification of biosignals to emotion classes. This chapter starts with an introduction on biosignals for emotion detection. Next, a state-of-the-art review is presented on automatic emotion classification. Moreover, guidelines are presented for affective MMI. Subsequently, a research is presented that explores the use of EDA and three facial EMG signals to determine neutral, positive, negative, and mixed emotions, using recordings of 21 people. A range of techniques is tested, which resulted in a generic framework for automated emotion classification with up to 61.31% correct classification of the four emotion classes, without the need of personal profiles. Among various other directives for future research, the results emphasize the need for parallel processing of multiple biosignals

ProPIG - Organic pig health, welfare and environmental impact across Europe

Organic production is perceived by consumers as being superior in animal welfare and sustainability and the demand for organic pork products is slowly increasing. Within the past ten years a variety of husbandry and management systems have been developed across the EU, ranging from farms with pigs outdoors all year round using local breeds to farms with housed pigs having concrete outside runs and using conventional breeds (CorePIG, Rousing et al, 2011). So far, mainly clinical parameters have been used to describe the health situation on organic pig farms, identifying some key problems, such as weaning diarrhoea and piglet mortality. Organic pig production is - amongst others - characterised through a holistic approach based on the EU Regulation (EC) No 834/2007 and the IFOAM principles: ‘health, ecology, fairness and care’. This clearly states that health is more than absence of clinical symptoms and, the relation between animals and their environment is identified: ‘Health’ is defined as ‘the wholeness and integrity of living systems. It is not simply the absence of illness, but the maintenance of physical, mental, social and ecological well-being’ (IFOAM; 2006). Concepts of animal welfare include physical and mental welfare as well as the concept of naturalness (Fraser 2003), which is often interpreted as the ability to perform natural behaviour. Verhoog et al (2003) describe three main approaches within organic agriculture’s concept of nature and naturalness: the no-chemicals approach, the agro-ecology approach and the integrity approach. Applying those concepts to organic pig production can highlight potential conflicts: outdoor systems are perceived as the optimal housing system for pigs, as they allow natural behaviour such as rooting. However, this behaviour can cause damage to the grass cover and furthermore the manure fate in outdoor areas needs to be considered. A few studies on outdoor pig production have shown a clear N and P surplus and a high degree of distribution heterogeneity in outdoor areas, increasing the risk of N and P losses (Watson et al. 2003). Robust and competitive organic pig production needs to encompass low environmental impacts and good animal health and welfare. So far few studies have quantified both aspects in different pig husbandry systems. In addition, the theory that improving animal health and welfare reduces environmental impacts through decreased medicine use, improved growth rate and feed conversion efficiency has still to be verified. The aim of the CoreOrganic2 project ProPIG (2011-2014; carried out in eight European countries) is to examine the relationship between health, welfare and environmental impact. On-farm assessment protocols will be carried out on 75 farms in three pig husbandry systems (outdoor, partly outdoor, indoor with concrete outside run). Environmental impact will be assessed using both Life Cycle Assessment and calculations of nutrient balances at farm and outdoor area level. Animal health and welfare will be evaluated from animal based parameters including clinical and selected behavioural parameters. Results will be fed back and used by the farmers to decide farm specific goals and strategies to achieve these goals. As an outcome, all farms will create their individual health, welfare and environmental plan, which will be reviewed after one year to allow continuous development. This will provide the opportunity not only to investigate, but also improve the influence of organic pig farming systems on animal welfare and environmental impact. This fulfils the fourth IFOAM principle of care: ‘Organic Agriculture should be managed in a precautionary and responsible manner to protect the health and well-being of current and future generations and the environment’ (IFOAM, 2006)

Random Series and Discrete Path Integral methods: The Levy-Ciesielski implementation

We perform a thorough analysis of the relationship between discrete and series representation path integral methods, which are the main numerical techniques used in connection with the Feynman-Kac formula. First, a new interpretation of the so-called standard discrete path integral methods is derived by direct discretization of the Feynman-Kac formula. Second, we consider a particular random series technique based upon the Levy-Ciesielski representation of the Brownian bridge and analyze its main implementations, namely the primitive, the partial averaging, and the reweighted versions. It is shown that the n=2^k-1 subsequence of each of these methods can also be interpreted as a discrete path integral method with appropriate short-time approximations. We therefore establish a direct connection between the discrete and the random series approaches. In the end, we give sharp estimates on the rates of convergence of the partial averaging and the reweighted Levy-Ciesielski random series approach for sufficiently smooth potentials. The asymptotic rates of convergence are found to be O(1/n^2), in agreement with the rates of convergence of the best standard discrete path integral techniques.Comment: 20 pages, 4 figures; the two equations before Eq. 14 are corrected; other typos are remove